U.S. patent number 4,227,174 [Application Number 05/891,670] was granted by the patent office on 1980-10-07 for distress/hazard signal flasher.
This patent grant is currently assigned to Robert A. Belcher. Invention is credited to Gregg D. Ahumada, Robert A. Belcher.
United States Patent |
4,227,174 |
Belcher , et al. |
October 7, 1980 |
Distress/hazard signal flasher
Abstract
An automotive lamp flasher provides a visibly irregular series
of flashes to indicate the existence of a distress situation. The
flasher also provides a regular series of flashes as is done by
existing flashers. Circuitry is provided to generate a nonuniform
pulse train and repeatedly apply this pulse train to a lamp
activation circuit. Broadly, a multiplexer with a plurality of
input terminals is used, each having a logic level thereon. The
multiplexer is sequentially stepped to provide an output
representative of the sequence of logic levels on the input
terminals. Preferred stepping means includes a timer for supplying
a continuous sequence of uniformly spaced pulses, and a scaler
responsive to these pulses for supplying a sequence of binary codes
to the multiplexer.
Inventors: |
Belcher; Robert A. (San Rafael,
CA), Ahumada; Gregg D. (San Rafael, CA) |
Assignee: |
Belcher; Robert A. (San Rafael,
CA)
|
Family
ID: |
25398628 |
Appl.
No.: |
05/891,670 |
Filed: |
March 30, 1978 |
Current U.S.
Class: |
340/471;
340/321 |
Current CPC
Class: |
B60Q
1/385 (20130101); B60Q 1/46 (20130101); G08B
5/002 (20130101); G08B 5/38 (20130101); B60Q
2900/10 (20130101) |
Current International
Class: |
G08B
5/22 (20060101); B60Q 1/34 (20060101); G08B
5/38 (20060101); B60Q 1/38 (20060101); B60Q
1/46 (20060101); B60Q 1/26 (20060101); G08B
5/36 (20060101); G08B 005/38 (); B60Q 001/26 () |
Field of
Search: |
;340/81,321,340,384E,378 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Yusko; Donald J.
Attorney, Agent or Firm: Townsend and Townsend
Claims
We claim:
1. Apparatus for flashing a plurality of lamps on a vehicle, the
lamps being operatively coupled to at least one lamp activation
means, comprising:
output terminal means adapted to be coupled to the lamp activation
means,
the output terminal means having a first state wherein the lamp
activation means is enabled, and a second state wherein the lamp
activation means is disabled;
first pulsing means adapted to be coupled to the output terminal
means for any arbitrary desired duration for causing the output
terminal means to alternately assume its first state and its second
state, wherein the time intervals during which the output terminal
means is in its first state are of substantially equal length, and
wherein the time intervals during which the output terminal means
is in its second state are of substantially equal length, thus
defining a uniform pulse sequence;
second pulsing means adapted to be coupled to the output terminal
means for any arbitrary desired duration for causing the output
terminal means to alternately assume its first state and its second
state, wherein at least two of the time intervals during which the
output terminal means is in its first state are of unequal length,
thus defining a non-uniform pulse sequence which is repeatedly
applied to the output terminal means for as long as the second
pulsing means is coupled to the output terminal means; and
manually actuable selection means operatively coupled between the
first pulsing means, the second pulsing means and the output
terminal means for selectively coupling the first pulsing means or
the second pulsing means to the output terminal means.
2. Apparatus for controlling lamp activation means to flash a
plurality of lamps on a vehicle according to a predetermined time
sequence comprising:
output terminal means adapted to be coupled to the lamp activation
means such that a pulse train appearing at the output terminal
means causes the lamp activation means to flash the lamps according
to a time sequence representative of the pulse train appearing at
the output terminal means;
a plurality of input terminal means, each input terminal means
adapted to receive a logic signal;
a corresponding plurality of logic signal generating means, each
said means applying a logic signal to a corresponding input
terminal means;
uniform pulsing means for generating a first uniform pulse
train;
means responsive to the uniform pulsing means for sequentially
coupling signals on the plurality of input terminal means to the
output terminal means;
such that a pulse train appears at the output terminal means, the
pulse train being a serial representation of the logic signals on
the plurality of input terminal means;
whereby the lamps are flashed according to a time sequence
representative of the sequence of logic signals applied to the
plurality of input terminal means;
means for coupling the uniform pulsing means to the output terminal
means wherein a second uniform pulse train representative of the
first uniform pulse train appears on the output terminal means;
and
manually actuable selection means having a first position wherein
the means for coupling the uniform pulsing means to the output
terminal means is activated and wherein the sequential coupling
means is deactivated and a second position in which the uniform
pulsing means is deactivated and the sequential coupling means is
activated.
3. The invention of claim 2 wherein the sequential coupling means
includes scaler means, and multiplexing means coupled to the scaler
means.
4. Apparatus for simultaneously activating a plurality of lamps on
an automobile according to either of two modes, the first mode
being a uniform sequence of pulses, the second mode being a
non-uniformly spaced sequence of pulses, comprising:
timing means for generating a first uniform pulse train wherein the
pulses have uniform spacing and uniform duration;
lamp activation means adapted to cause the lamps to be
illuminated;
output terminal means coupled to the lamp activation means wherein
a logic signal appearing at the output terminal means causes the
lamp activation means to illuminate the lamps responsively to and
representative of the logic signal;
an ordered plurality of input terminal means, at least one of which
input terminal means is at a first logic level and at least another
of which input terminal means is at a second logic level;
first coupling means responsive to the timing means and adapted to
sequentially couple the logic levels on the ordered plurality of
input terminal means to the output terminal means;
means responsive to the timing means for generating a second
uniform pulse train wherein the pulses have uniform spacing and
uniform duration;
second coupling means adapted to couple a logic signal
representative of the second uniform pulse train to the output
terminal means; and
manually actuatable selection means having a first position wherein
the first coupling means is disabled and the second coupling means
is enabled, and a second position wherein the first coupling means
is enabled and the second coupling means is disabled.
wherein the lamps are activated according to the first or second
mode when the selection means is in its first or second position
respectively.
5. The invention of claim 4 wherein the pulses of the second
uniform pulse train have their spacing substantially equal to their
duration.
6. Apparatus for simultaneously activating a plurality of lamps on
an automobile according to either of two modes, the first mode
being a sequence of uniformly spaced pulses, the second mode being
a non-uniformly spaced sequence of pulses, comprising:
timing means for generating a first uniform pulse train wherein the
pulses have uniform spacing and uniform duration;
lamp activation means adapted to cause the lamps to be
illuminated;
output terminal means coupled to the lamp activation means wherein
a logic signal appearing at the output terminal means causes the
lamp activation means to illuminate the lamps responsively to and
representative of the logic signal;
scaler means operatively coupled and responsive to the first
uniform pulse train of the timing means for repetitively generating
a serial sequence of binary codes;
an ordered plurality of input terminal means, at least one of the
input means being at a first logic level and at least one other of
the input terminal means being at a second logic level, each input
terminal means corresponding to at least one binary code;
multiplexer means operatively coupled to the scaler means for
generating a logic signal representative of the logic level on one
of the input terminal means when the binary code from the scaler
means corresponds to that input terminal means;
such that the serial sequence of binary codes causes the
multiplexer means to produce a first non-uniform pulse train that
is a serial representation of the logic signals on the plurality of
input terminal means;
means responsive to the least significant bit of the binary code
for generating a second uniform pulse train wherein the pulses have
uniform spacing and uniform duration, and spacing between pulses
being substantially equal to the duration of the pulses; and
manually actuatable selection means for selectively and exclusively
coupling to the output terminal means pulse trains representative
of the first non-uniform pulse train and the second uniform pulse
train;
whereby the lamps are flashed in one of the two modes depending on
the position of the manually actuatable selection means.
7. The invention of claim 6 wherein the binary code has a number of
bits corresponding to the integer n, and the plurality of input
terminal means has a number of input terminal means corresponding
to the integer 2.sup.n.
8. The invention of claim 6 wherein the selection means comprises a
switch having at least two positions, and a plurality of logic
gates operatively coupled between the switch, the multiplexer
means, the second uniform pulse train generating means, and the
output terminal means.
9. The invention of claim 6 wherein the lamp activation means
includes a transistor operatively coupled to the output terminal
means, the transistor having a conducting state and a
non-conducting state and being capable of being switched between
said states according to the time sequence of the pulse train
appearing at the output terminal means, and a relay operatively
coupled to the transistor such that the relay causes the lamps to
be illuminated when the transistor is in its conducting state.
10. In combination with an automobile having a plurality of signal
lamps and lamp activation means, an improved flasher unit for
selectively flashing the signal lamps according to either of a
first uniform mode and a second non-uniform mode comprising:
output terminal means coupled to the lamp activation means;
manually actuable selection means having a first position and a
second position;
first pulsing means for generating a uniform pulse train and
applying the uniform pulse train to the output terminal means when
the selection means is in its first position;
second pulsing means for producing a non-uniform pulse train and
for applying the non-uniform pulse train to the output terminal
means continuously and repeatedly when the selection means is in
its second position, thus causing the lamps to be activated in a
visibly irregular flashing manner corresponding to the non-uniform
pulse train.
11. The invention of claim 11 wherein the second pulsing means
comprises:
multiplexer means having a plurality of input means at respective
logic levels to define the non-uniform pulse train; and
means for sequentially and cyclically coupling the logic levels on
the multiplexer means inputs to the output terminal means so that a
pulse train representative of the sequence of logic levels on the
input terminals appears at the output terminal to define the
non-uniform pulse train.
12. A method of providing either of two degrees of warning to
people outside an automobile having a plurality of signal lamps
from within the automobile, comprising the steps of:
providing manually actuable selection means having first and second
positions;
communicating a first uniform pulse train to a plurality of signal
lamps on the automobile when the selection means is in its first
position; and
communicating a second non-uniform pulse train to the plurality of
lamps during the time interval that the selection means is in its
second position.
Description
BACKGROUND OF THE INVENTION
Modern automobiles are invariably equipped with a so-called
"emergency flasher" which, when activated by the driver,
simultaneously activates flashing lights on all four corners of the
vehicle. These lights are often the same lights that are also used
as turn signals. While these four-way flashers may have originally
been intended to provide indications of an emergency situation,
increased and often indiscriminate use by the driving public has
degraded the impact of these emergency flashers so that they
provide no more than an indication that the vehicle is stopped, and
is likely to remain so for more than an instant. Thus the emergency
flasher does provide a very useful safety feature in that it tends
to protect stopped cars from being hit by moving cars. However,
there still exists the need for a device whereby a driver can
signify to other drivers that a distress situation exists and that
he needs help.
A common way of indicating that help is needed is to erect a flag,
typically on the radio antenna. Since many newer cars have radio
antennae built into the windshield glass, and since many
automobiles do not have radios at all, it is also a practice to tie
a handkerchief to the door handle.
The use of a flag-like indicator is not without its problems. The
driver must get out of the automobile to place the flag in a
visible position. This may be dangerous to the driver, may be
undesirable due to bad weather, and may even be impossible, as for
example, if the driver has become incapacitated. Moreover, a flag
may not be visible in bad weather, especially at night.
Another way of signalling to passing motorists that a distress
situation exists is the placement of verbal signs on the rear ledge
of the automobile so that they can be seen through the rear window.
However, such signs tend to become lost or damaged so that they are
not available when need for their use arises. Also, snow, dirt,
window fog, or glare can prevent the sign from being visible. In
addition, an incapacitated driver may be physically incapable of
reaching over to the back ledge to place the sign in position.
U.S. Pat. No. 3,226,707 to Newman et al. discloses a device which
overcomes some of these difficulties. Basically, it is a
permanently mounted fixture with a variety of internally stored
signs, any one of which can be placed in a position for viewing.
While such a device provides for relatively easy actuation by a
disabled driver, it still relies on visibility through the rear
window. Moreover, a permanent fixture for signs may be unsightly,
can interfere with driver visibility out of the rear window, and is
likely to be relatively expensive.
SUMMARY OF THE INVENTION
The present invention is an automotive device for providing an
indication to other motorists that aid is required. The device is
easily actuable, provides an indication which is highly visible
while having no external manifestation when not in use, and can be
adapted to existing wiring in the car without substantial
modification. Broadly, the invention is an improved four-way
flasher which is capable of providing a visibly irregular sequence
of flashes, to indicate the existence of a distress situation. The
invention also has the capability of providing a regular sequence
of flashes as is done by existing flashers.
The improved flasher contains circuitry for providing a pulse train
wherein the pulses have non-uniform spacing and duration, and for
repeatedly applying this pulse train to a lamp activation circuit.
Broadly, a multiplexer with a plurality of input terminals is used,
each having a logic level thereon. The multiplexer is sequentially
stepped to provide an output representative of the sequence of
logic levels on the input terminals. Preferred stepping means
includes a timer for supplying a continuous sequence of uniformly
spaced pulses, and a scaler responsive to these pulses for
supplying a sequence of binary codes to the multiplexer.
According to one aspect of the invention, the circuitry is packaged
so as to be plug compatible with existing automotive flasher wiring
sockets. This is preferably in the form of a small box having two
or three prongs, depending on the socket. Thus the improved flasher
can be easily substituted for the existing flasher in an
automobile. A selector switch, preferably mounted within easy reach
of the driver allows selection of either a uniform or a non-uniform
pulse train. In the two-prong version, a ground connection for the
circuitry may be taken from the switch.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating the principle of the
invention.
FIG. 2A is a circuit diagram of the invention, suitable for
replacing existing 3-prong flashers.
FIG. 2B is a circuit diagram of the invention, suitable for
replacing existing 2-prong flashers.
FIG. 3 is an exploded perspective view showing a preferred
packaging of the electronic circuitry of FIG. 2A in a form
especially adapted to be fitted into existing automobile flasher
circuits.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning to the drawings, FIG. 1 sets forth the basic functioning of
the present invention. Broadly, a plurality of lamps on an
automobile is caused to flash on and off in a fashion
representative of one of two electrical pulse trains. The first
pulse train is uniform, i.e., the pulses are equally spaced and of
equal duration. The second pulse train is non-uniform in that
either the spacing or duration of the pulses varies from pulse to
pulse. Reference timer 4 provides a uniform sequence of pulses to
pulse train generator 6. Non-uniform pulse sequence selector 8
defines the sequence of non-uniform pulses. Pulse train generator 6
supplies a uniform pulse train on line 10, and a non-uniform pulse
train on line 12. Pulse train selector 14, which preferably
includes manually actuatable means transmits a pulse sequence
representative of the selected pulse train to amplifier/activator
16, thereby activating lamps 18. Thus, the uniform pulse train
results in a regular flashing sequence, as is provided by existing
automobile flashers. The non-uniform pulse train causes an
irregular sequence of light flashes which is used to signify a
distress situation.
FIGS. 2A and 2B show preferred embodiments of circuitry for
realizing the functions set forth in FIG. 1. Solid state integrated
circuit elements (to be described below) are used. Each of these
elements has a configuration of pins that is industry-standard, and
references to pin numbers refer to the standard configuration for
the element in question.
Referring to FIG. 2A, reference timer 4 of FIG. 1 preferably
comprises a type 555 timer 20 such as that manufactured by
Fairchild Camera and Instument Corporation, Mountain View, Cal.,
94042 (herein after Fairchild), 20K resistor 22 is connected
between pins 7 and 8, 1K resistor 24 between pins 6 and 7, and 22
microfarad capacitor 26 between pin 6 and ground. Pin 8 is
connected to a 5-volt power supply (as described below), and pin 1
is grounded. Pin 2 is shorted to pin 6, and pin 4 is shorted to pin
8. Pin 3 is connected to line 30.
Pulse train generator 6 and non-uniform pulse sequence selector 8,
both of FIG. 1 together comprise scaler 32 and multiplexer 34.
Scaler 32 may be a type 7493 4-bit binary counter manufactured by
Fairchild. Pin 5 of Scaler 32 is connected to the 5-volt power
supply and pin 10 is grounded. Pins 1 and 12 are shorted, and pins
2 and 3 are shorted and tied to ground. Line 30 is input to pin 14
on counter 32. Pins 12, 9, 8, and 11 are connected to 4-bit data
line 36 which comprises individual lines 38, 39, 40 and 41. Pin 12
of Scaler 32 is also connected to output line 48.
Multiplexer 34 may be a type 74150 manufactured by Fairchild. Pin
24 of multiplexer 24 is connected to the 5-volt power supply and
pin 12 is grounded. Pin 9 is grounded. Lines 38-41 are input to
pins 15, 14, 13 and 11 of multiplexer 34. Pin 10 of multiplexer 34
is connected to output line 50.
Multiplexer 34 has 16 input data lines 60-75, connected to pins 1-8
and 16-23 respectively. Each line may be supplied with a low logic
level by being shorted to ground, or may be supplied with a high
logic level by being left open or tied to the supply voltage
through a large value resistor. The choice of which of data lines
60-75 to provide with a low or high logic level is dictated by the
desired irregular sequence of pulses as will be more fully
described below.
Pulse train selector 14 of FIG. 1 preferably comprises a selector
switch 80 having a pole 88 and contacts 90 and 92, and three nand
gates 82, 84, and 86. Selector switch 80 is preferably a single
pole-double-throw slide or toggle switch having pole 88 grounded
and contacts 90 and 92 connected to lines 94 and 95 respectively.
Lines 94 and 95 are connected to the 5-volt supply through 22K
resistors 96 and 97 respectively.
Gates 82, 84 and 86 are preferably part of a type 7400 quad two
input nand gate chip manufactured by Fairchild. Only 3 of the 4
nand gates of the chip are used. Lines 50 and 94 are input to nand
gate 82 (connected to pins 1 and 2). Lines 48 and 95 are input to
nand gate 84 (connected to pins 4 and 5). Pins 3 and 6
corresponding to the output from nand gates 82 and 84 respectively
are connected to lines 98 and 100 respectively. Lines 98 and 100
are inputs to nand gate 86 (connected to pins 9 and 10). Pin 8, the
output of nand gate 86 is connected to line 110.
Amplifier/activator 16 of FIG. 1 preferably comprises a transistor
120, a relay 124, a damper diode 126, and a 1K resistor 128.
Transistor 120 has its emitter grounded, and its base connected to
line 110 through 1K resistor 128. The collector of transistor 120
is connected through the activation coil of relay 124 to the
positive terminal of the automobile battery 120. Damper diode 126
connected across relay 124 in the collector circuit is back biased
and protects the transistor from excess voltage build up which may
occur when transistor 120 is turned off and the coil field of relay
124 collapses.
Transistor 120 may be a type 2N2222 NPN transistor. Diode 126 may
be type 1N4001. Relay 124 is a 12 volt relay having a resistance in
its activation coil in the range of 1.2K. Relay 124 has a pole 130
and contacts 132 and 134. Contact 132 is left open, and contact 134
is connected to the positive terminal of the battery. Pole 130
engages contact 132 when relay 124 is not activated, and engages
contact 134 when relay 124 is activated. Pole 130 of relay 124 is
connected to line 136.
The entire circuit gets its power from the automobile battery. The
integrated circuit elements typically require a stabalized 5-volt
power supply. Since the car battery provides a voltage (6-volt or
12-volt) that is above this value and is furthermore subject to
fluctuation, the circuit must also contain its own 5-volt power
supply. A 5 volt zener diode 142 is therefore used which has its
anode grounded. A 47 ohm resistor 114 is connected between its
cathode and the positive battery terminal. The resulting 5-volt
level, suitable for supplying the integrated circuit components is
taken off the cathode of zener diode 142 on line 146.
The circuit as described above is preferably packaged as shown in
FIG. 3. The circuit elements, shown schematically in phantom, are
mounted to a small circuit board 150 which is housed in a box 152.
Box 152 is preferably molded from an insulating material such as
plastic, and has a cover 154 which may be bolted or otherwise
fastened in place. Existing automotive flasher modules are of
either a 2 or 3 prong design. The first prong is connected to the
positive battery terminal, and the second is connected to one
terminal of the lamps to be activated (the second terminal of the
lamp to be activated being connected to ground). The third terminal
(if any) is grounded. The operation of the flasher is such that the
second terminal is repetitively shorted to the first, thereby
energizing it with the battery voltage. In between, the second
terminal is an open circuit. The above-described packaging of the
present invention is designed to allow the present invention to be
used in existing automobiles to replace existing flasher modules.
FIG. 3 illustrates a 3-pronged device having metal prongs 156, 157,
and 158, which are adapted to the standard automobile wiring
sockets. Although the configuration of prongs may vary from one
automobile manufacturer to another, it may be assumed for
illustration purposes that prong 156 communicates to the automobile
battery's positive terminal, that prong 157 communicates to the
vehicle ground (the battery's negative terminal) and that prong 158
communicates to the lamps to be flashed. Prongs 156, 157, and 158
communicate to the circuit board and the elements thereon by wires
160, 161 and 162 respectively. Selector switch 80, and more
particularly contacts 90 and 92 thereof are connected to the
circuit by a multiple conductor 164 (which includes lines 94 and
96, of sufficient length that switch 80 can be mounted at a
position where it is readily acceptable to the driver of the
vehicle. Thus the switch might be mounted near the existing flasher
actuation switch.)
Referring to FIGS. 2A and 3, it can be seen that the circuit
elements within dashed rectangle 180 of FIG. 2A correspond to those
circuit elements on circuit board 150 that fit within box 152. The
3 prongs 156, 157, and 158 in both figures correspond to the same
items.
FIG. 2B shows circuitry for use in a 2 prong installation. The
circuitry is the same as that in FIG. 2A, except that prong 157 of
FIG. 2A which communicates ground to the internal circuit elements
is not present. Rather, ground for the circuit is supplied from
pole 88 of switch 80, which is grounded by its mechanical
connection to the automobile. Thus, it is necessary for an extra
lead between switch 80 and the circuit elements within dashed
rectangle 180'. Extra wire 182 leads from grounded pole to the
circuits.
Having thus described the circuitry, the operation can be
understood. Timer 20 provides a uniform sequence of pulses at pin 3
which are output on line 30. The repetition rate is determined by
the voltage divider comprising 20K resistor 22 and 1K resistor 24.
Resistor 22 may be varied to achieve a pulse repetition rate in the
range of 2-4 pulses per second, which is twice the standard flasher
frequency (typically required to be in the range of 1-2 pulses per
second). Counter 32 counts the pulses on line 30, and generates a
binary code on lines 38-41, according to the number of pulses that
have come in on line 30. In the preferred embodiment, counter 32 is
a 4-bit counter having four output lines corresponding to 16 binary
states. The outputs on individual lines 38, 39, 40, and 41 are
uniform pulse trains with frequencies that are divisions of the
frequency of pulses on line 30, the reduction being by factors of
2, 4, 8, and 16, respectively. Also each of these four pulse trains
has its pulse duration equal to the interval between pulses. Thus,
the output on line 48 (the same as the output on line 38) is
suitable for driving lamps at the standard flasher frequency. It is
the nature of the operation of binary counter 32 that the sequence
of binary codes generated on four-bit line 36 repeats itself after
16 pulses have come in on line 30.
The binary code on lines 38-41 is fed to multiplexer 34. Depending
on the binary code input to multiplexer 34, the logic level on the
corresponding data line 60-75 will appear, inverted, on multiplexer
output line 50. Thus, the sequence of pulses on line 50 is
representative of the sequence of data line levels. Since the
sequence of binary code on 4-bit line 36 recycles every 16 pulses
from timer 20, a sequence of 16 logic levels is provided, that
sequence repeating itself every 16 pulses from timer 20.
While it would be possible to set the logic levels on lines 60-75
in any one of a number of ways without departing from the spirit of
this invention, two preferred sequences are set forth in the
following table, referenced below as Table 1.
______________________________________ (logic level) (multiplexer
line) (0 = low, 1 = high) ______________________________________ 60
0 1 61 1 1 62 0 0 63 1 1 64 1 0 65 1 0 66 0 1 67 0 0 68 0 1 69 1 1
70 1 0 71 0 1 72 1 0 73 0 0 74 1 1 75 1 0
______________________________________
FIGS. 2A and 2B illustrate the connections for the first and second
sequences respectively.
Selector switch 80 determines which pulse sequence, the regular one
on line 48, or the non-uniform one on line 50, is output on line
110. When pole 88 is connected to contact 90, thereby putting a low
level on line 94, the output from nand gate 82 on line 98 is
constantly high. At the same time, given the high level on line 95
to nand gate 84, the output on line 100 is the inverse of the pulse
train on line 48. Given the condition on lines 98 and 100, the
output on line 110 is the inverse of the pulse train on line 100,
or equivalently, it follows the pulse train on line 48. Similarly,
if selector switch 80 is set with pole 88 contacting contact 92,
the output on line 110 is the pulse train on line 50. Thus, the
selector switch and the nand gates serve to put one of the pulse
trains on line 110.
The pulse train on line 110 turns transistor 120 on in a
corresponding fashion, thereby energizing relay 124 accordingly.
Thus, terminal 158 is connected to the battery voltage in a fashion
corresponding to the pulse train on line 110. It should be noted,
that since the multiplexer output on line 60 is inverted with
respect to the logic levels on lines 60-75, the sequence of flashes
is complimentary to the sequence of logic levels on lines
60-75.
Referring to Table 1, it can be seen that the first sequence of
levels gives rise to a pattern of flashes that is basically a long
flash (levels on lines 66-68) with four short flashes occurring
before the next long flash. The second sequence results in a
repetitive series of short-long-short flashes.
* * * * *